Realistic Fermion Masses and Nucleon Decay Rates in SUSY SU(5) with Vector-Like Matter

TL;DR

Adding vector-like matter to SUSY SU(5) models corrects fermion mass relations, improves gauge coupling unification, and predicts nucleon decay rates within experimental reach for TeV-scale spectra.

Contribution

Introducing a vector-like 5+5bar pair in SUSY SU(5) to fix fermion mass relations and enhance gauge unification while maintaining proton decay predictions.

Findings

Corrected fermion mass relations with vector-like matter.

Improved gauge coupling unification.

Predicted nucleon decay rates accessible at experiments.

Abstract

We show that by adding a vector-like 5+5bar pair of matter fields to the spectrum of the minimal renormalizable SUSY SU(5) theory the wrong relations for fermion masses can be corrected, while being predictive and consistent with proton lifetime limits. Threshold correction from the vector-like fields improves unification of gauge couplings compared to the minimal model. It is found that for supersymmetric spectra lighter than 3 TeV, which would be testable at the LHC, at least some of the nucleon decay modes should have partial lifetimes shorter than about 2.10^34 yrs., which is within reach of ongoing and proposed experiments.